In order to ensure the end-to-end Quality of Service (QOS) of service transportation, the International Telecommunication Union (ITU-T) defines the network architecture of resource and admission control functions (RACFs) of Next Generation Networks (NGN). Referring to FIG. 1, in this network architecture, an RACF 120 is introduced between a service control function (SCF) 110 and a transport function (TF) 130 for implementing negotiation and reservation of end-to-end transport resources for a service at an access network and a backbone network bearing the service.
In some application scenarios, the user experience of a service is closely correlated to the delay of service application. For example, a user is sensitive to the delay in channel switching when using a broadcast television (BTV) service. In order to solve this problem, a service application method is provided in the prior art.
In the RACF architecture, according to different application scenarios, two bearer resource reservation modes are defined, namely, a push mode and a pull mode.
FIG. 2 is a flow chart of service application in the push mode.
201, a customer premises equipment (CPE) 150 sends a “service request” message (for example, SIP Invite and HTTP Get) to the SCF 110 to apply for a service.
202, the SCF 110 extracts/generates QoS parameters (for example, bandwidth) required by the service, and then sends a “resource reservation request” message containing the QoS parameters to the RACF 120, so as to request authorization and reservation of bearer resources.
203, the RACF 120 performs authorization and admission control according to operator policy rules, use conditions of the bearer resources, and a user profile in a network attachment control function (NACF) 140. If the admission is granted, the RACF delivers control strategies such as gate control, packet marking, and bandwidth allocation to the TF 130.
FIG. 3 is a flow chart of service application in the pull mode.
301, the CPE 150 sends a “service request” message (for example, SIP Invite) to the SCF 110 to apply for a service.
302, the SCF 110 extracts/generates QoS parameters (for example, bandwidth) required by the service, and then sends a “resource reservation request” message containing the QoS parameters to the RACF 120, so as to request authorization of bearer resources.
303, the RACF 120 performs authorization verification according to operator policy rules. If the service is authorized, an authorization token is assigned to the service.
304, the SCF 110 sends information such as the token to the CPE 150.
305, the CPE 150 initiates a bearer resource reservation request the service to be applied through a QoS signaling at the bearer layer. The request contains the token assigned by the RACF 120.
306, upon receiving the bearer resource reservation request, the TF 130 at the edge of the network sends a “resource reservation request” message containing the token to the RACF 120, so as to request reservation of the bearer resources.
307, the RACF 120 performs admission control according to operator policy rules, use conditions of the bearer resources, and a user profile in the NACF 140. If the admission is granted, the RACF delivers control strategies such as gate control, packet marking, and bandwidth allocation to the TF 130.
The inventor of the disclosure has found through studies that interactive processing of multiple network elements such as SCF, RACF, NACF and TF is required for each service application. Moreover, since the SCF is generally located at the network core domain when networking is actually performed, a message needs to be transferred from the CPE to the SCF through multiple network equipments, resulting in a long delay in processing the service application and rendering the service that is sensitive to the delay of service application hard to be deployed.